1. Field of the Invention
The invention relates to an internal combustion engine and a control method for an internal combustion engine.
2. Description of Related Art
Japanese Patent Application Publication No. 2012-021501 (JP 2012-021501 A) describes a control system for an internal combustion engine including a tumble control valve that generates a tumble flow in a cylinder. In the control system described in JP 2012-021501 A, an estimated tumble ratio is calculated on the basis of a detected value of a first air flow meter provided upstream of a throttle valve and a detected value of a second air flow meter provided just downstream of the tumble control valve. The opening degree of the tumble control valve is subjected to feedback control so that the estimated tumble ratio follows a target tumble ratio. The target tumble ratio is set to a value within an allowable control range for avoiding misfire or instable combustion.